Point me to documentation that says this, because this smacks of I-see-on-Mac-and-expand-to-fill-all-mental-space. The Thunderbolt specification doesn't make any such restriction, and neither does the underlying PCIE topology.
Instead, say, "Apple's esthetic is no clutter/choice is confusing, so they chose for you by implementing Thunderbolt in a serial fashion."
Of course, I'm glad to be wrong if you can show a statement that says Thunderbolt is daisy-chain only.
You are correct Thunderbolt can be configured in many ways, as below.
The Thunderbolt protocol physical layer is responsible for link maintenance including hot-plug detection, and data encoding to provide highly efficient data transfer. The physical layer has been designed to introduce very minimal overhead and provides full 10Gbps of usable bandwidth to the upper layers.
The heart of the Thunderbolt protocol architecture is the transport layer. Some of the key innovations introduced by the transport layer include:
•A high-performance, low-power, switching architecture.
•A highly efficient, low-overhead packet format with flexible QoS support that allows multiplexing of bursty PCI Express transactions with isochronous DisplayPort communication on the same link.
•A symmetric architecture that supports flexible topologies (star, tree, daisy chaining, etc.) and enables peer-to-peer communication (via software) between devices.
•A novel time synchronization protocol that allows all the Thunderbolt products connected in a domain to synchronize their time within 8ns of each other.
DisplayPort and PCI Express protocols are mapped onto the transport layer. The mapping function is provided by a protocol adapter which is responsible for efficient encapsulation of the mapped protocol information into transport layer packets. Mapped protocol packets between a source device and a desti- nation device may be routed over a path that may cross multiple Thunderbolt controllers. At the destination device, a protocol adapter recreates the mapped protocol in a way that is indistinguishable from what was received by the source device.
Information taken from
www.thunderbolttechnology.net
